It depends.
I personally found tutoring for English to be quite helpful and worth it to me in High School as it gave me more opportunity to practice my writing until I got the hang of it for the HSC. However, that isn't to say that tutoring is for everyone.
Tutoring for English itself varies from tutor to tutor and centre to centre. Ideally a good tutor would be one that would be able to address your concerns, weaknesses, and give you additional practice on your school's texts whilst allowing for ample opportunity to practice your writing comprehension and essay skills.
Your best bet is always to first try consulting your school teacher if you need help looking over and getting feedback for things such as your essays. If you aren't satisfied with that or you find that you're looking for something a little bit more than tutoring might be an option for you.
Hope that helps.